NIR spectroscopy is used in the process control methods within the food industry because the spectra associated with a foodstuff may provide information about the chemical bonds contained within a foodstuff under test. With suitable calibration, a detected spectrum for a test foodstuff can be used to determine the concentration of various components of the test foodstuff, such as water (e.g. moisture), protein, fat and carbohydrate. Herein, the term “foodstuff” may mean a material used at any stage during the production of a food product, i.e. any ingredient, intermediate substance or even the final product itself.
Conventional NIR spectroscopy techniques use a diode array detector to detect the spectrum of a foodstuff, which is subsequently analysed to obtain information about the constituents of the foodstuff.